Paying Attention to Power

E-mail Melanie Martella

We are in love with our mobile devices, and with good reason; they are tremendously useful things, in large part because of the combination of highly compact built-in smarts and a supporting infrastructure and ecosystem. We may focus on the ooh-shiny aspects, but underneath it all lies the issue of power consumption: how much we use and where we get it from.

While clever use of technology can help us to be more efficient, whether it's smarter HVAC systems, smart motors, and a raft of other products and systems that let us optimize our environments and activities, those technologies also consume energy. And, as I learned last week when I was attending the MEMS Executive Congress in Scottsdale, AZ, energy consumption of such information and communication technologies is growing very, very fast. Ajith Amerasekera from Texas Instruments gave a talk about ultra-low-power electronics and why they are so important. To start, I'll share one of the facts about cloud computing from his talk that boggled my mind: If the cloud were a country, it would be the fifth largest consumer of energy, and its energy consumption is growing. That's pretty startling, right?

It's not just a question of figuring out ways to make server farms, data warehouses, and communication networks more efficient, although that's definitely important. It's also about making the devices that connect to the cloud and networks more efficient, too. Streaming takes energy, mobile devices take energy, and powering the wireless infrastructure that makes our devices so necessary to us takes a huge amount of energy. While better batteries are never a bad thing, the energy demand is exceeding the ability of current battery technology to improve its energy density (again according to Ajith), so we need new technologies that offer greater capacity, more charge cycles, and faster charge rates. (Did you know that current lithium ion batteries have a greater energy density than a grenade? I didn't. Now I can't decide whether I think that's cool or worrisome. It may be a toss-up.) I'll add that if it's a rechargeable battery, the electricity to recharge it has to come from somewhere, too.

Ultra-low-power electronics is one of the enabling technologies for the kind of pervasive computing/Internet of Things we seem to be inching towards, a dependable and autonomous environment that anticipates our needs, adapts to us, and is controllable (unless a massive storm comes through, in which case all bets may be off). It's not the only thing required, by any stretch of the imagination, but smaller, more efficient, lower-power electronics is key if we are to move from the idea to practical implementation. Heck, consider wireless sensors that require both a small form factor and low-power operation to achieve longevity and utility! If you're interested in learning more, you can view the slides from Ajith's May 2011 IEEE Solid-State Circuit Society (SSCS) Distinguished Lecture here (PDF). which are educational and thought-provoking.